1. Field of the Invention
The present invention relates to a multiple photo-metering apparatus for obtaining a proper exposure value by photo-metering a plurality of areas in a field and by coordinating photometric results regarding the respective areas, and more particularly, it relates to a three-dimensional multi-pattern photo-metering apparatus adapted to select one of various exposure determining methods including e.g., a method wherein the photometric value regarding the central area of the field is weighted to determine the exposure value and a method wherein the exposure value is determined by an average value of the photometric values regarding all of the areas, and the like, in accordance with conditions of the field, in order to obtain a proper exposure value from the photometric values.
2. Description of the Related Background Art
In multi-pattern photo-metering apparatuses of this kind, as disclosed in the U.S. Pat. No. 4,412,730, an exposure determining method comprised of dividing the field into a central area and several peripheral areas surrounding the central area, photo-metering the respective areas and determining exposure information used for controlling the exposure, on the basis of the plural photometric values regarding the respective areas has been proposed.
In this conventional photo-metering apparatus, field luminance or brightness of each of the areas corresponding to plural photometric outputs is obtained, and a single exposure information is determined by utilizing several reference informations such as the obtained maximum brightness, minimum brightness, average brightness, maximum brightness difference, brightness regarding the central area and the like.
In order to determine such exposure information, several of the above-mentioned reference informations, for example, the maximum brightness and the maximum brightness difference are compared with a predetermined condition, respectively, thereby selecting a single exposure information calculated on the basis of the results of comparison regarding such reference information.
Now, in taking a photograph of an object, if the main object is a person, the exposure regarding the background is generally not so important, but the exposure regarding the person is regarded as important; whereas, if the object consists of a landscape, the balance of the whole landscape is regarded as important.
However, in the above-mentioned construction of the conventional apparatus, since the exposure information was determined on the basis of the same condition both when the main object is a person having an object distance of, for example, 3 meters and when the object is a landscape having an object distance.infin., it was not always possible to obtain an optimum exposure value with respect to various main objects.